Dynamic Deformation Behavior of Zr-Based Amorphous Alloy Matrix Composites Reinforced with STS304 or Tantalum Fibers

Abstract

The Zr-based amorphous alloy matrix composites reinforced with stainless steel (STS) or tantalum (Ta) continuous fibers were fabricated without pores or defects by liquid pressing process, and their dynamic deformation behaviors were investigated. Dynamic compressive tests were conducted by a split Hopkinson pressure bar, and then the test data were analyzed in relation to the microstructures and the deformation modes. In the STS-fiber–reinforced composite, the STS fibers could interrupt the propagation of cracks initiated in the matrix and promoted the continuous deformation without fracture according to the strain-hardening effect of the fibers themselves. The Ta-fiber–reinforced composite showed the higher yield strength than the STS-fiber–reinforced composite, but the cracks were not interrupted properly by the Ta fibers according to the lower ductility and strain hardening of the Ta fibers. Both the Ta and STS fibers favorably affected the strength and ductility of the composites by interrupting the propagation of cracks formed in the amorphous matrix, by dispersing the stress applied to the matrix, and by promoting deformation mechanisms such as fiber buckling. The STS-fiber–reinforced composite showed the higher compressive strength and ductility than the Ta-fiber–reinforced composite because the STS fibers were higher in the resistance to deformation and fracture than the tantalum fibers.